HeliBoard 1.3-beta1

Changes since HeliBoard 1.2:

• change icons for autocorrect and select all toolbar keys by @codokie (#524, #651)
• add Chuvash layout by @tenextractor (#677)
• add cut toolbar key by @codokie (#678)
• update Probhat layout by @fahimscirex (#628)
• show toolbar icons in toolbar key dialog
• add close button in clipboard history by @codokie (#403, #649)
• add Russian (Student) layout by @Zolax9 (#640)
• make numpad on symbols key long press optional (#588)
• minor fixes and improvements, including #632, #637, #638 by @RHJihan